Approach Categories

摘要

Aircraft approach categories basically are established to ensure adequate obstacle clearance when maneuvering during the circling approach portion of a procedure. They are based on a speed of 1.3 times the airplane's stall speed in the landing configuration at maximum gross weight. This speed often is referred to as Vs1. By "landing configuration," of course, we mean putting down the gear and extending full flaps, so the appropriate indicated airspeed is not only published but present on your airspeed indicator: It's the bottom of the white arc. The illustration at right depicts the various ways in which we can maneuver to a runway after an approach while the table below lists the five approach-speed categories and the protection they afford, which is represented by the radius, r, in the illustration.